Inductively coupled plasma torch structure with protected injector

Abstract

An inductively coupled plasma (ICP) torch is described that includes an injector protector to shield an injector end. A system embodiment includes, but is not limited to, a tubular sample injector configured to receive an aerosolized sample in an interior defined by walls of the tubular sample injector; an injector protector surrounding at least a portion of the tubular sample injector; an inner tube surrounding at least a portion of the injector protector to form a first annular space between the inner tube and the injector protector, the inner tube defining at least one inlet port for introduction of an auxiliary gas into the first annular space; and an outer tube surrounding at least a portion of the inner tube to form a second annular space, the outer tube defining at least one inlet port for introduction of a cooling gas into the second annular space.

What is claimed is: 
     
         1 . An inductively coupled plasma torch, comprising:
 a tubular sample injector configured to receive an aerosolized sample in an interior defined by walls of the tubular sample injector;   an injector protector surrounding at least a portion of the tubular sample injector, at least a portion of each of the tubular sample injector and the injector protector being tapered inwardly in a direction from an inlet end of the inductively coupled plasma torch and an outlet end of the inductively coupled plasma torch;   an inner tube surrounding at least a portion of the injector protector to form a first annular space between the inner tube and the injector protector, the inner tube defining at least one inlet port for introduction of an auxiliary gas into the first annular space; and   an outer tube surrounding at least a portion of the inner tube to form a second annular space, the outer tube defining at least one inlet port for introduction of a cooling gas into the second annular space.   
     
     
         2 . The inductively coupled plasma torch of  claim 1 , wherein an output end of at least one of the tubular sample injector, the injector protector, and the inner tube is positioned within the outer tube. 
     
     
         3 . The inductively coupled plasma torch of  claim 1 , wherein an output end of each of the tubular sample injector, the injector protector, and the inner tube is positioned within the outer tube. 
     
     
         4 . The inductively coupled plasma torch of  claim 1 , wherein an output end of the injector protector is substantially flush with an output end of the inner tube. 
     
     
         5 . The inductively coupled plasma torch of  claim 4 , wherein an output end of the tubular sample injector extends beyond the output end of the injector protector. 
     
     
         6 . The inductively coupled plasma torch of  claim 4 , wherein an output end of the tubular sample injector is substantially flush with the output end of the injector protector. 
     
     
         7 . The inductively coupled plasma torch of  claim 4 , wherein the output end of the injector protector extends beyond an output end of the tubular sample injector. 
     
     
         8 . An inductively coupled plasma torch, comprising:
 a tubular sample injector configured to receive an aerosolized sample in an interior defined by walls of the tubular sample injector;   an injector protector surrounding at least a portion of the tubular sample injector, at least a portion of each of the tubular sample injector and the injector protector being tapered inwardly in a direction from an inlet end of the inductively coupled plasma torch and an outlet end of the inductively coupled plasma torch;   an inner tube surrounding at least a portion of the injector protector to form a first annular space between the inner tube and the injector protector, the inner tube defining at least one inlet port for introduction of an auxiliary gas into the first annular space;   an outer tube surrounding at least a portion of the inner tube to form a second annular space, the outer tube defining at least one inlet port for introduction of a cooling gas into the second annular space; and   a gas introduction sheath coupled to an input end of each of the tubular sample injector and the injector protector for introduction of a gas between the tubular sample injector and the injector protector, the gas introduction sheath defining a gas inlet port configured to receive the gas for introduction to a third annular space defined between the injector protector and the tubular sample injector.   
     
     
         9 . The inductively coupled plasma torch of  claim 8 , wherein an output end of at least one of the tubular sample injector, the injector protector, and the inner tube is positioned within the outer tube. 
     
     
         10 . The inductively coupled plasma torch of  claim 8 , wherein an output end of each of the tubular sample injector, the injector protector, and the inner tube is positioned within the outer tube. 
     
     
         11 . The inductively coupled plasma torch of  claim 8 , wherein an output end of the injector protector is substantially flush with an output end of the inner tube. 
     
     
         12 . The inductively coupled plasma torch of  claim 11 , wherein an output end of the tubular sample injector extends beyond the output end of the injector protector. 
     
     
         13 . The inductively coupled plasma torch of  claim 11 , wherein an output end of the tubular sample injector is substantially flush with the output end of the injector protector. 
     
     
         14 . The inductively coupled plasma torch of  claim 11 , wherein the output end of the injector protector extends beyond an output end of the tubular sample injector. 
     
     
         15 . An inductively coupled plasma torch, comprising:
 a tubular sample injector configured to receive an aerosolized sample in an interior defined by walls of the tubular sample injector;   an injector protector surrounding at least a portion of the tubular sample injector;   an inner tube surrounding at least a portion of the injector protector to form a first annular space between the inner tube and the injector protector, the inner tube defining at least one inlet port for introduction of an auxiliary gas into the first annular space, an output end of the injector protector being substantially flush with an output end of the inner tube, and an output end of the tubular sample injector extending beyond the output end of the injector protector; and   an outer tube surrounding at least a portion of the inner tube to form a second annular space, the outer tube defining at least one inlet port for introduction of a cooling gas into the second annular space.